How to transfer whatsapp conversations from iphone 3G to iphone 4s?

Hi! I;m getting a new iphone 4s and i would like to know if there's a way to transfer my whatsapp conversations from my old phone(iphone 3G) to my new one (iphone 4s)

Back up the phone in iTunes
Restore from the backup in iTunes

That will also see about transferring all the content/settings etc from the 3G to the 4S.